We Feel Fine / by Jonathan Harris and Sepandar Kamvar
It’s not just pretty. This applet polls various rss feeds and collects posts where people describe how they feel. Then it uses various relationships and attributes to present that data in innovative ways.
These various graphs are playful and informative. Found this via MonkeyBites, which has a great writeup. Also of note is an API so that other artists can use this search without having to do the backend coding.